1. Field of the Invention
This invention relates to a new and improved collapsible film food package suitable for vacuum storage of frozen fresh or cooked foods at low temperature and for an extended period of time. The food package of this invention allows repeated opening and closing to facilitate the addition and/or removal of food without significant loss of flavor or edibility.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
The food packaging industry includes vacuum or non-vacuum sealed food products, many of which packages are intended for use in storage at extremely low temperatures over long periods of time. Products include raw meat, poultry, fish, and other sea foods such as crustaceans, fresh vegetables, fully cooked foods such as pizza, and frozen confections such as ice cream.
Current re-sealable vacuum packages utilizing zipper strips and a flat disk check valve for removal of air from the interior of the containers. These packages are limited to a flat configuration, namely bags. Testing has indicated that these seals provided by the zipper strips fail to maintain vacuum over-night in about 20-30% of the time. A flat disk check valve is used in the current re-sealable vacuum food packages on the market. Testing has further found that sometimes it is difficult to aspirate air by a vacuum pump even when the food package is placed on a hard flat table surface.
The problem with presently designed factory sealed food packages is two-fold, the first being that ice is formed on the food content if the package is sealed without vacuum and the second being that no measures are provided to reseal the package for restoring the vacuum following opening of the sealed package for addition of food or for removing a portion of its content. In both cases, when the seal is broken to allow removal and/or addition of food, the entry of air and moisture into the package frequently causes ice formation. The result is a deterioration of the food and a reduction in flavor and edibility. Also the long term storage viability of the food contained therein is reduced upon resealing.
Various patents have been disclosed pertaining to closures and sealing systems for food packages, and they include U.S. Pat. Nos. 4,941,310; 5,009,828; 5,070,584; US 2003/0152296 A1; U.S. Pat. No. 6,692,147; B2; 2004/0114837 A1; 2004/0161178 A1; 2005/0196077 A1; 2005/0244083 A1; and, 2007/0110340 A1. However, as noted, supra, none of the above patents provide a solution to the problem of ice formation and air and moisture contamination following opening of a food package to access the contents therein. Also, these patents do not provide long term vacuum sealing at very low temperatures for square or cylindrical food containers.